


Slither Into My Heart

by IvyPrincess



Series: Snake Tales [1]
Category: NCT (Band)
Genre: Basilisks, Cuddling & Snuggling, Fluff, Fluff and Humor, Humor, Hybrids, Immortality, Kissing, Lab Experiments to Lovers, Lamiae, M/M, Pre-Relationship, Rivals to Lovers, Shapeshifting, Snakes, look nomin are big magic snakes and renjun is their pet mad scientist what more do you want from me
Language: English
Status: Completed
Published: 2020-08-19
Updated: 2020-08-19
Packaged: 2021-03-06 01:02:05
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,758
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25984819
Author URL: https://archiveofourown.org/users/IvyPrincess/pseuds/IvyPrincess
Summary: Lab protocol didn’t seem to approve of falling in love with your specimens, but, well, Renjun's never been much of a stickler for the rules.
Relationships: Huang Ren Jun/Lee Jeno, Huang Ren Jun/Lee Jeno/Na Jaemin, Huang Ren Jun/Na Jaemin, Lee Jeno/Na Jaemin
Series: Snake Tales [1]
Series URL: https://archiveofourown.org/series/1890187
Comments: 61
Kudos: 288





	Slither Into My Heart

**Author's Note:**

> This is 1000% Imjaebabie's and tenspetal's faults. Thank them, blame them, whatever you want. Also this is based off [this](https://twitter.com/ex_aItiora/status/1295316583842230273) tweet.

When Jaemin wakes up again, he’s still in chains. Much like yesterday, the day before, and the day before _that_. Not that he minds much, since they can’t do anything to hinder his movement if he just shifts his legs away again. And so he does just that, watching smooth human skin melt away into glittering purple scales, until everything below his torso becomes a massive serpentine tail again. Ah yes, much better. He slithers out of his restraints, only a single metal cuff left on his very human wrist, linking him through a long chain to a ring bolted into the wall. Jaemin frowns. He could very well yank it out of the stone, arm flexing in preparation to do just that, but _oh_ , he had promised the sweet little doctor that he’d at least try to behave.

Jaemin cheers up at the thought that he’ll soon see his darling again, just a glimpse of his cute frown enough to keep the lamia pliant for an entire day. It's almost time for their weekly checkups, and if he's lucky, maybe he'll even be able to steal a kiss or five from Dr. Huang again. Jaemin sighs dreamily as his tail whips around behind him in excitement, settling down onto his scaly coils to wait. That's the nice thing about solitary confinement, it gives him room to steal his love away for some _alone time_.

Unfortunately, the clomp of footsteps approaching his cell don't sound anything like the soft whisper of Dr. Huang's loafers, and Jaemin's eyes narrow to thin slits in displeasure.

"Morning, tall, dark, and scaly," Donghyuck drawls, hands shoved deep in the pockets of a white lab coat that drapes almost all the way down to those thick-soled combat boots. "You know the drill, let's not have a fight today, shall we?" His menacing grin flashes white against tan skin, and Jaemin rises up on his tail to a full 7 feet to look down on the other man in affront.

"Your shoes are against regulation," he haughtily informs the human, crossing his arms in front of him. "Renjunnie will be upset."

Donghyuck scoffs as he pulls a huge ring of keys out of his pocket and unlocks the metal door. "Please, the ghouls were chewing on each other again today, you try wading through decomposing slime without getting it all over you." Despite his posturing, Jaemin wouldn't do much to harm Donghyuck. Permanently, that is. Renjun's rather fond of his bitchy lab assistant, unfortunately. He's led out of his cell with minimal fuss, although smugness oozes out of every pore when he manages to trip Donghyuck with his lengthy tail. He's promptly handcuffed and dragged out of his cell. Jaemin hopes Donghyuck works up a sweat trying to lug all fifteen feet of him down to the clinical wing.

Ten years of captivity have bred too much familiarity between Jaemin and the rough-hewn walls of these corridors, and he thinks that he could easily escape in his sleep by now, but something stays his flight every time. It's a bit embarrassing for an immortal of his stature to be caught so easily after a shedding, but he _had_ been distracted by the fierce little gray-haired human heading his capture. Humanity had come too far from the last time he'd encountered their kind, and Jaemin had been ill-prepared for the needle jabbing into his ribs, the resulting drowsiness slowing his movements enough for them to tangle him in a net.

He supposes it's not all bad. For an evil scientist intent on stealing the secrets of immortality from the legends that roam this land, Dr. Huang is surprisingly humane, artificial environments set up underground to mimic the natural habitats of most of the creatures held captive, and Jaemin is fed monthly, which was honestly more than he needed, although he'd never prevent Renjun from inadvertently spoiling him. There are some things the humans just don't need to know.

Donghyuck slumps to the ground in front of a heavy iron door, panting. Jaemin in his natural form is _heavy_ , to say the least, although the lamia likes to think he's just helping contribute to Donghyuck's exercise routine. He brushes purple bangs out of his eyes before rising up again, human torso upright, serpent tail coiled demurely beneath him. "Thank you for the lift, Hyuckie," he coos in that syrupy tone Donghyuck hates. "I'll take it from here~" The brunet puddle on the floor flips him off.

When Jaemin enters the room, for one brief moment, he forgets he's actually still underground. The vast space, probably an old gladiator arena (Renjun inherited the lab facilities from some ancestral villain who had a _thing_ for violence), is filled with sweet-smelling grasses, a small brook burbling away from the entrance, disappearing into a thicket of young trees on the far side of the chamber. It's a place of sanctuary, for those creatures having trouble adjusting to captivity, and Renjun had always preferred to observe their behavior when they were relaxed, more genuine in their actions.

Beneath him, the floor fades away from concrete slabs to soft earth, damp scent fresh in his nostrils. It reminds him of his birthplace, eons ago when he had only been a child, brightly colored tail waving languidly in the sun as he held his breath underwater, honing his reflexes by trying to snatch fish with his bare hands.

Jaemin's not the only one here, though. His little stint with Donghyuck had cost him a lot of traveling time, and as he scents the air, slithering towards the small forest, he realizes that someone has stolen his favorite basking rock, where he likes to preen and soak up the sun in all manners of elegant poses for Dr. Huang to sketch. Oh, this _bastard_.

"Jeno," Jaemin hisses, fangs elongating involuntarily as he glares down at the black basilisk lounging in his spot. "Get _off_."

The asshole doesn't even bother opening his eyes in his snake form, only yawning widely so his own fangs, lethally curved and four times the size of Jaemin's, appear, and Jaemin pouts. Fine, if Jeno won't leave, then he'll just have to make him.

The lamia hoists himself onto the rock in the meager space Jeno isn't taking up, using the space he has to slither further on top of Jeno, blushing furiously at the intimacy of cool scales sliding against his own until he can sit in a more human position atop Jeno's head, coiling the rest of his tail tightly around Jeno's jaw until he resembles an oversized headdress. Jaemin contracts his snake half once out of pure spite, when there's a low impatient rumble coming beneath him, before Jeno raises his head and Jaemin yelps as his entire body ascends until his head is level with the treetops, Jeno having raised his head in irritation.

Suddenly, there's a large pop of displaced air, and then Jaemin is plummeting back to the ground with a surprised yelp, but the impact of his tail against stone never comes, and instead he lands in Jeno's very sturdy, very human lap, bright yellow eyes glaring sullenly at him, the tip of a fang digging into pouty lips. Jaemin hurriedly rolls out of his lap at the endearing sight, scooping up his tail so no part of him is touching the basilisk anymore.

"You could've just asked me to move over," Jeno grumbles sleepily, head at a tilt, black bangs flopping into his eyes.

Jaemin hisses defensively. "No, you scaly log, first you steal my Renjunnie, and now my basking stone, too?"

Jeno sighs, sensing that Jaemin is in one of his moods again. "Jaemin, he was just doing my checkup, too, like he does for everyone."

Jaemin sniffs, nose in the air. "Well, there's no other scalekin here, is there? And we know how partial Junnie is to those of us with venom." He flicks his tail smugly, the jewel tones glittering beautifully in the imitation sunlight.

Jeno snorts. "Of course we have his attention, it decomposes before he can extract any useful compounds from it, so he can't figure out what marker contributes to our lifespan."

Before Jaemin can retort that Dr. Huang still likes him better than Jeno, another lab tech they're familiar with appears, looking for all the world like he's gone a few rounds with a pillow. And lost.

"Sorry I'm late," Mark wheezes, hacking up another feather, its dusty down matching the color of the feathers jutting out of his hair. "Harpy containment took longer than I thought. One of the girls broke a wing, so Renjun's overseeing her splinting right now. Jaemin, can you stretch out all the way for me so I can get your measurements?"

Jaemin droops. He's been looking forward to this all week, and now he won't even see his darling doctor. "Renjunnie can't make it?" Jeno moves forward to console him, before remembering Jaemin's opinion of him right now and thinking better of it.

Mark frowns apologetically. "Well, maybe I can take you to him later?" He pulls out a measuring tape. "If we can finish quickly, I can even take you to the canteen so you can bring him one of those little cakes he likes."

Jaemin immediately perks up, snatching the tape out of Mark's hand with his tail and stretching out so Mark can jot everything down. He obediently lets Mark shine a light in his eyes (ouch), drip some venom in a glass tube (ugh), and recites how he's been feeling lately (bored) before waiting impatiently as the same is done to Jeno.

"Okay, everything looks good!" Mark peers down at his clipboard, checking his numbers one last time. "Jeno, Renjun has your bloodwork done, so you might as well come with us now, too." They'll be weighed later, to make sure they're properly adjusting to the change of seasons, but for now, their checkups are over.

As soon as Mark puts his pen away, Jaemin is already scooping the researcher up in his arms and slithering as fast as he can back to the entrance, not even looking back to see if Jeno can keep up. To his credit, Mark doesn't try to wriggle out of his grasp, not even when Jaemin skids back into the cold hallways and races down the hall towards their canteen, only pausing so he can swipe Mark's ID in the card reader.

When he bursts through the doors, every eye is immediately on him. A fork falls from an intern's slack jaw to clatter loudly against the floor.

"Hello!" Jaemin grins cheerfully, carefully setting Mark down on his feet. "I seek the cake!" Mark looks a bit green. Jaemin doesn't think humans are supposed to be able to turn colors beyond pink.

"S-security breach," someone in the crowd whimpers. They must be new.

Regardless, Jaemin gets his cake easily enough, a delightful little strawberry-flavored thing that he carefully clutches to his chest, shrinking back down to his human legs to avoid jostling it too much before he can present it to Renjun. He beams at Miss Boa in thanks. He's always had a soft spot for her: she has such a wonderful name, after all. The head nutritionist shakes her head wryly in response, pointedly looking away from his nude form.

Suddenly, there's a piece of fabric fluttering in front of his eyes as Jeno ties his shirt around Jaemin's waist as a makeshift apron to cover his crotch. Jaemin frowns at the feeling of his rival's arms around him, but allows him to finish unimpeded. Humans are a bit funny about not wearing clothes, although Jaemin's never liked the restrictive garments. Besides, he can't risk destroying the cake in a tussle.

They make their way slowly to the other side of the facility, keeping pace with Jaemin's slow walking speed, and although they get a few strange looks from the other lab techs scurrying around, Mark's presence means no one stops them on their way.

Renjun's office is empty, though, and Mark is a little wary about leaving the snakes in the place with no supervision, so they head to one of the renovated lab spaces that's little more than a conference room now. Donghyuck is there, squinting at some papers through round glasses, and Jaemin puts his animosity aside to share a sly glance with Jeno as Mark's body heat spikes, flushing to the tips of his ears.

"H-hey, uh, Donghyuck." Mark fumbles with his words, although the younger man doesn't acknowledge their presences at all. "Renjun's coming back here soon, right?"

Donghyuck finally sets his papers down to raise an eyebrow at Mark. "Yes, we're reviewing the manticore room designs in an hour, as you should know, considering you were overseeing the proposal."

Mark laughs sheepishly, scratching the back of his head, but the motion causes his elbow to catch on his lanyard, and as he just about keels over trying to untangle himself, Jaemin sighs impatiently. "Can you tell Renjunnie to come faster? I brought him cake."

"And he has bloodwork results for me," Jeno pipes up, probably just to undermine Jaemin's efforts. Rude.

Donghyuck stares at the obstinate serpents for a moment longer before sighing and tossing his papers down and getting up to swipe them into the back room. "Fine. Guess he's not doing that review with us then, knowing how long you two are going to stall him." Jaemin cheerfully brushes past him and shifts back into his tail, coiling up with the cake secure in his lap. Donghyuck rolls his eyes at how happy he looks before leaving again, voice fading as he calls out to Mark to stop tripping over his own feet or the manticores are going to eat him alive, damn it.

Then it's just Jaemin and Jeno, who has pulled up a chair and is poring over one of the binders by the computer. It's a little quiet for Jaemin, especially in such close quarters with Jeno, and he lets his eyes drift over the small room, which is probably just large enough for two serpents of his and Jeno's size to curl up in. Besides the computer desk and small bookshelf, there's no other furniture except a small cot in the corner behind a privacy screen, where the researchers occasionally nap for a bit when they're too tired to make it back to their own quarters.

The window on the wall is actually a repurposed scrying mirror, transitioning between views of the various sanctuary areas in the lab. Jaemin blinks sleepily as the blue light of the marine room washes over his face. In the corner of the view, a mermaid tail flicks out of sight. There are little sleeping nooks like this hidden all over the facility, but only Renjun really uses this one and has done so recently, judging by the strong lavender scent emanating from the lab coat slung carelessly over the end of the bed.

It's also the nook closest to Jaemin's own quarters, which he tries not to be too pleased by. A cold draft whispering through the room draws a violent full-tail shiver from Jaemin, who, unclothed and reptilian, is starting to slow down from the strong A/C. He twists in a circle uneasily, trying to keep moving in the limited space he has, but it doesn't help much, and he wants to make sure his pretty tail is all on display for Renjun when he comes in.

"Jeno," he whines quietly, setting the cake down on the shelf and slithering closer so he can rest his head on Jeno's knees. "I'm cold..." He trails off as the breeze blows by him again. As a creature from a cursed bloodline, Jaemin was much more closely related to mundane snakes, and thus was much more susceptible to low temperatures than Jeno who, as a true basilisk, was fully warm-blooded in his human form.

Jeno hums absently but complies and sits down in the middle of the floor so Jaemin can leech his body heat and coil his entire length around Jeno's body. The basilisk strokes one warm hand absently over his scales, and Jaemin sighs happily as he warms up just a touch.

Unlike most of the other specimens, Jeno had given Renjun permission to study him closely, if one was to believe the rumors flying around. Jaemin has no idea, since Jeno's been here for years even before Jaemin was brought in, but the lamia supposes he can't see a basilisk prince being caught by mere humans, even if Jeno was like 119th in line to the throne or something.

Basilisks laid a _lot_ of eggs.

Regardless, it means Jaemin is ridiculously jealous of their close relationship, although Jeno seems to tolerate his antics calmly enough. Sometimes, though, like now, Jaemin just wants to rile Jeno up, whether Renjun's involved or not. The atmosphere was getting a little too cuddly for his liking, even if he was the one who instigated it.

"Renjun likes me more than you," Jaemin announces out of the blue, and Jeno finally puts the binder down long enough to stare skeptically at the lamia in his lap. "He does," Jaemin insists, puffing his cheeks out as he stares up at the other with big, blue eyes.

Jeno catches on quickly, looking amused that Jaemin wants to pick a fight now of all times. "Then why's he up all night diluting my venom?" He shoots back, letting Jaemin pick the binder up with his tail and toss it onto the cot.

Jaemin sniffs haughtily. "Well, you've been here longer than me and he still hasn't moved you to your own chamber yet. What's it like living next to the kitsune?"

Jeno's mirth only seems to grow. "Jaemin, Renjun moved _you_ away because your restlessness was driving them up the wall too, and no one could handle the allure battle brewing between you and Yuta."

Instead of sulking, Jaemin preens. "Stupid fox thought he could seduce more people than me. Anyways, I got a two-hour lecture from Renjun afterwards." He's starry-eyed just thinking of how adorable the human was when he was mad.

Jeno laughs. "Well, if you want to go there, my blood diagnostics say 'abnormal' and 'potentially hazardous' in his own handwriting. How could you possibly compete with that?"

Jaemin pouts. "Well, I'm going to kiss him first this time!"

"Who's doing what?" Comes a tired voice from the doorway, and Jaemin squeals in pure joy, launching himself at his beloved mad scientist and peppering his cheeks with light kisses as he carries Renjun back to the center of the room, where Jeno waves sheepishly, eyes shuttered green with his secondary eyelids so Renjun can look him in the eye without dropping dead.

"Can I kiss you? Pleaaase?" Jaemin wheedles.

Despite the dark circles beneath his eyes, Renjun laughs. "Haven't you been kissing me since I walked in the room?"

Jaemin pouts. "No, a real kiss." He glances at Jeno, who nods imperceptibly. "You weren't in the forest today. I had to get measured by _Mark_."

Renjun reaches up to cup the lamia's cheek, smiling gently as the snake nuzzles into his touch. "Alright, since you've had such a hard time today without me, hm?"

Jaemin ignores the tease, concentrating on drawing up the magic from his core. Renjun might not be able to sense it, but Jeno's form seems to darken as _his_ core responds to the serpent magic in the air. "Renjun," Jaemin asks sweetly, voice layering, although Renjun is too mundane to notice. "May I have this kiss please?"

Renjun sighs in mock exasperation. "Why do you two have to ask every time?" The scientist glances over at Jeno, who looks all too interested but doesn't protest. "Yes, the answer is always yes."

As soon as he has consent, Jaemin draws Renjun's face closer, licking over Renjun's lips until his human opens his mouth with a tiny gasp, letting venom pool in the back of his mouth and drip down between Renjun's teeth. Given willingly, snake venom has extremely strong healing properties, and as magical creatures, it's so potent that it's the secret to immortality that Renjun's been looking for all this time. Not that he and Jeno will ever tell their darling, anyway. They've kept him in the dark for more than a decade now, it's honestly a surprise he hasn't even suspected yet.

Jaemin tugs Renjun in closer by the waist, other hand stroking up to cup the back of his head. Renjun's lips are so soft against his own, parting even further as Jaemin swipes his venom-coated tongue against Renjun's bottom lip, and Renjun moans, falling slack in Jaemin's grip. They part for air, venom and saliva dripping down Renjun's chin, and Jaemin draws back just enough to notice Renjun swallowing slightly after licking over his own lips. Good, he's taken in some of the venom, but perhaps Jaemin needs to make sure he's gotten enough of a dose.

"Why do you two always taste so _good_ ," Renjun groans, fisting a hand in Jaemin's hair as he tugs the lamia's head back down to crush their mouths together. This kiss is even needier than the last, harder, rougher, and Jaemin allows Renjun to take the lead, greedily helping himself to everything Renjun is willing to give. He's about to break off to suggest they give Jeno a turn, too (what, he's learned how to share) when Renjun does something absolutely sinful with his tongue, swiping across the sensitive spot near Jaemin's fang, and now it's Jaemin's turn to moan, coiling more of his tail around both of them, trying to press their bodies impossibly closer.

Finally, it takes a slight cough from Jeno to have him reluctantly pull back from their sweet little scientist, and Jaemin is very pleased at how Renjun now looks more overwhelmed than tired, lips shiny and pink from their kiss. He loosens his hold enough that Renjun can escape from his coils and sit heavily down on the cot next to Jeno, who promptly wraps an arm around the human.

Jaemin slithers over to settle in their laps, tail curled demurely around their feet, all but purring as Jeno cards his fingers through Jaemin's messy purple fringe. Now that he's fed Renjun his weekly dose of venom, they can get to the _real_ business.

Jaemin winds further upright until he's settled between both of them, staring adoringly at Renjun.

"I got you _cake_."

**Author's Note:**

> might be a series in the future. find me on [twitter](https://twitter.com/1vyPrincess) and [cc](https://curiouscat.me/IvyPrincess)


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